31 research outputs found
Shrinking a large dataset to identify variables associated with increased risk of Plasmodium falciparum infection in Western Kenya
Large datasets are often not amenable to analysis using traditional single-step approaches. Here, our general objective was to apply imputation techniques, principal component analysis (PCA), elastic net and generalized linear models to a large dataset in a systematic approach to extract the most meaningful predictors for a health outcome. We extracted predictors for Plasmodium falciparum infection, from a large covariate dataset while facing limited numbers of observations, using data from the People, Animals, and their Zoonoses (PAZ) project to demonstrate these techniques: data collected from 415 homesteads in western Kenya, contained over 1500 variables that describe the health, environment, and social factors of the humans, livestock, and the homesteads in which they reside. The wide, sparse dataset was simplified to 42 predictors of P. falciparum malaria infection and wealth rankings were produced for all homesteads. The 42 predictors make biological sense and are supported by previous studies. This systematic data-mining approach we used would make many large datasets more manageable and informative for decision-making processes and health policy prioritization
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
W boson polarization measurement in the ttbar dilepton channel using the CDF II Detector
We present a measurement of boson polarization in top-quark decays in
events with decays to dilepton final states using of integrated luminosity in collisions collected by the
CDF II detector at the Tevatron. A simultaneous measurement of the fractions of
longitudinal () and right-handed () bosons yields the results
and . Combining this measurement
with our previous result based on single lepton final states, we obtain and . The results are consistent with standard
model expectation.Comment: Published in Phys. Lett.
PUBERTAL MATURATION OF THE LH STIMULATORY RESPONSE TO CLOMIPHENE CITRATE IN CONGENITAL VIRILIZING ADRENAL HYPERPLASIA
LINEAR GROWTH AND PUBERTAL DEVELOPMENT IN TREATED CONGENITAL ADRENAL HYPERPLASIA DUE TO 21-HYDROXYLASE DEFICIENCY
Production of K0S, K*±(892) and Ï0(1020) in minimum bias events and K0S and Î0 in jets in ppÂŻ collisions at sâ=1.96ââTeV
We report measurements of the inclusive transverse momentum (pT) distribution of centrally produced K0S, Kâ±(892), and Ï0(1020) mesons up to pT=10ââGeV/c in minimum bias events, and K0S and Î0 particles up to pT=20ââGeV/c in jets with transverse energy between 25 and 160 GeV in ppÂŻ collisions. The data were taken with the CDF II detector at the Fermilab Tevatron at sâ=1.96ââTeV. We find that as pT increases, the pT slopes of the three mesons (K0S, Kâ±, and Ï) are similar. And using our previous Î0 results from minimum bias events, we show that the ratio of Î0 to K0S as a function of pT in minimum bias events becomes similar to the fairly constant ratio in jets at pTâŒ5ââGeV/c. This suggests that the particles with pTâł5ââGeV/c in minimum bias events are from âsoftâ jets, and that the pT slope of particles in jets is insensitive to light quark flavor (u, d, or s) and to the number of valence quarks. We also find that for pTâČ4ââGeV relatively more Î0 baryons are produced in minimum bias events than in jets